摘要
利用室内矩形水槽,精细模拟了5个工况下的槽内水流运动,借助三维超声波多普勒测速仪(ADV)量测了不同垂线、不同测点的瞬时流速。从4个角度拟合矩形断面明渠沿垂线的流速分布,并计算了测点三维相对紊动强度和雷诺应力,分析其变化特征。试验结果表明:①脉动流速基本符合正态分布,纵向流速沿垂线分布大体成J型,但在近水面处有稍许降低,横、垂向流速较小,在0附近徘徊;②通过4种公式拟合发现,对数公式d对本试验结果拟合最好;③横、垂向相对紊动强度比较小,而纵向要大得多,且变化幅度也较大,纵向相对紊动强度受流量和水量影响;④雷诺应力垂线分布基本符合三角形分布,随着流量的减少或水量的增大,雷诺应力垂线分布平均值变小。
Water movements in a rectangle flume under five working situations were simulated precisely. Three-dimensional ultrasonic Doppler speedometer ADV was used to measure velocities in different locations of the flume, The vertical distributions of velocity of the rectangle cross-sectlon of the flume were simulated from four sides. Then the three-dimensional relative turbulence intensity and Reynolds stress were calculated, and the changing characteristics were analyzed. The result of experiment indicates that （1） the pulsing velocity obeys the law of normal distribution, and the longitudinal distribution of velocity has the shape of ＂J＂, while the value becomes small near the water surface; the horizontal and vertical velocity is very small, almost at zero; （2） four formulas are used to simulate the distribution, among which the logarithmic formula of d is the best one; （3） the relative turbulence intensity of horizontal and vertical is very little, but the longitudinal is bigger with large ：fluctuation; the longitudinal relative turbulence intensity is influr enced by the factors of flux and water volume; （4） Reynolds stress distribution is according with the triangular, the average value becomes small with the decrease in flux or the increase in water volume.
出处
《中国农村水利水电》
北大核心
2007年第9期12-15,共4页
China Rural Water and Hydropower
关键词
明渠
流速分布
紊动强度
雷诺应力
open channel
distribution of velocity
turbulence intensity
Reynolds stress
